For the first time, cilantro is on the list of foods with high pesticide levels. It's yet another herb which consumers should be purchasing organic. Testing by federal scientists found 33 unapproved pesticides on 44 percent of the cilantro samples tested.

-- the highest percentage of unapproved pesticides recorded on any item since the Environmental Working Group started tracking the data in 1995. Mushrooms also make their first appearance on the Shopper's Guide as part of the Clean 15.

They analyzed pesticide residue testing data from the US Department of Agriculture and Food and Drug Administration to come up with rankings for these popular fresh produce items. Lower numbers = more pesticides.